The present invention relates to an adjustable rear supporting device particularly usable in ski boots composed of at least one quarter articulated to a shell.
It has been always an important problem, that of providing a optimal support to the back of the skier's leg in ski boots.
A French patent, no. 1,475,936 filed on Feb. 23, 1966, for example, discloses a ski boot in which an attempt has been made to solve this problem, but it had the disadvantage that a variation in the rear support entailed an increase in the circumference of the upper perimetric edge of said boot with a consequent reduction in the degree of securing of the leg.
A German patent, DE 2807371 filed on Feb. 21, 1978, discloses a device for the adjustment of the quarter with respect to the shell of a ski boot which has an eccentric element with a point of rotation on the shell or on the quarter.
Even this device, which allows the adjustment of the inclination of the quarter, also has a disadvantage: in fact it pushes the quarter vertically from below, and said quarter must therefore be moved forward, flexing the leg, in order to be able to actuate the device.
Without this operation, the adjustment would occur under stress, consequently requiring the skier to exert considerable efforts and possibly leading to the breakage of the device.
An improvement to the device of the above mentioned patent was provided by the same Applicant in the Italian utility model, No. 181178 filed on May 23, 1980, which discloses a device for the adjustment of the inclination of the upper quarter which comprises an abutment block which is associated with the rear part of the shell of the boot and is suitable for engaging by contact with the upper quarter to define its inclination, the peculiarity consisting of the fact that the block and the abutment can be positioned at various vertical levels on the upper quarter to vary the inclination.
However, even this solution has the disadvantage of requiring the forward inclination of the upper quarter in order to allow the activation of the device without excessive efforts.
Furthermore, although these devices provided an adjustment of the inclination of the quarter, they do not solve the problem related to the particular configuration of the calf of the skier, which is not adequately supported at the rear region of the rear quarter.
As a partial solution to this disadvantage as well, the same Applicant filed an Italian utility model application, No. 20463 B/86, on Jan. 13, 1986, wherein an upper quarter is articulated transversely at the rear end of the rear quarter of a boot and its position, and therefore its inclination with respect to the quarter, is actuated by means of an adapted lever which is pivoted to the rear quarter and interacts ratchet-like with a toothed band associated with the upper quarter.
Though undoubtedly effective, this solution has the disadvantage of being difficult to industrialize, due both to the particular configuration of the upper quarter and to the need to subsequently assembly all the components onto the boot.
The solution is therefore productively expensive.
In order to try to overcome these problems, which are thus related to constructive complications and to production costs, the same Applicant filed a patent application, No. 82550 A/88, on May 20, 1988, which discloses several solutions adapted to adjust the position of an upper quarter or, in any case, of a flap located at the rear region: even these solutions, however, are structurally not very simple and entail excessive manufacturing costs, which increase the overall cost of the boot.